This is going to be a short one guys. I'm just summing up the basic lessons to be learned from my first five posts about cryptography and what it has to do with how we implement cryptography today.
First things first. Entropy is the measurement of information in a message. More entropy, means that the message is harder to decipher. Reducing possibilities, even if it means you're obscuring the message, reduces entropy.
The overall goal when you're communicating is to basically make sure that whenever someone intercepts the message, it will take them long to decipher the message than the message is worth. Like I said before, messages decay over time.
A day old message is a military advantage.
A week old message is a history lesson.
The one-time pad is considered the gold standard of entropy. No way of doing it since then has even come close.
Cryptography is a constantly evolving field and the cryptography of the future will be able to crack modern-day ciphers.
Points of Weakness in Cryptography
Patterns can and will probably be exploited. Redundancy be it in the text or in the transmission gives the attacker a pattern to look for. Redundancy in the key, for example a poorly generated pad, gives the cryptologist a statistical advantage.
Most importantly, the weakest point of any cryptography is the human that is implementing it.
Like I said before guys, I'm just taking courses and reading documentation and sharing what I've learned to help better remember it. If you have any questions or feel like I've made a mistake so far in my learning please do let me know!